Laparoscopic living donor nephrectomy: a look at current trends and practice patterns at major transplant centers across the United States.

PURPOSE: Laparoscopic living donor nephrectomy is now the preferred technique for living donor renal transplantation. To our knowledge we provide the first published multi-institutional consensus describing practice patterns, technical considerations and interesting controversies involved in laparoscopic living donor nephrectomy. MATERIALS AND METHODS: We designed a survey with 33 multiple choice questions looking at demographics, patient selection, technical considerations, postoperative care and followup involved in laparoscopic living donor nephrectomy. Surveys were sent to the 58 fellowship training programs in the United States accredited by the American Society of Transplant Surgeons. RESULTS: The 32 responding programs performed approximately 40% of laparoscopic living donor nephrectomies in the United States in 2005. We found that almost all centers used a donor committee to screen candidates, enforce a body mass index cutoff, and use right kidneys when necessary and left kidneys in women of childbearing age. Regarding laparoscopic access, pure laparoscopy was favored 2 to 1 over the hand assisted technique and most of those who use nonbladed trocars do not close the fascia. Most surgeons divide the adrenal vein in left cases, use a vascular stapler on the renal artery and vein, and keep the ureter with the gonadal vein in the specimen. At most centers heparin is given before controlling the vessels. Extraction in pure laparoscopic cases is usually performed using a preplaced entrapment bag through a modified Pfannenstiel incision. CONCLUSIONS: Our survey describes how most renal transplant centers with accredited fellowship programs in the United States approach laparoscopic living donor nephrectomy. Specifically trends are revealed regarding patient selection, laparoscopic access and surgical technique.

Use of chemometrics to optimize the operation of an ion source.

A chemometric approach has been used to optimize the Agilent multimode ion source. Initial factorial experimental design studies indicated that there was a significant degree of curvature in the experimental region, so further central composite design experiments were performed. Optimum conditions were found using statistical optimization tools, and these results were then validated. As a result, recommendations have been made for the value of each operational parameter in order to optimize response.

Treatment of symptomatic caliceal diverticula using a mini-percutaneous technique with greater than 3-year follow-up.

BACKGROUND AND PURPOSE: Caliceal diverticula can be treated with a variety of techniques. Traditional percutaneous techniques utilize nephrostomy-tract dilation to between 26F and 32F. Identification of a small diverticulum can be difficult after such dilation. The mini-percutaneous nephrolithotomy technique has been described for the treatment of nephrolithiasis. We report on two patients with caliceal diverticula treated using a mini-perc technique with long-term follow-up. PATIENTS AND METHODS: Two symptomatic patients underwent treatment of posterior caliceal diverticula using a mini-perc technique. An interventional radiologist placed an 8F nephrostomy tube for access to the diverticulum. The following day, a 12F/14F ureteral access sheath was placed over a guidewire. Through the sheath, we identified the diverticulum and its neck with a 7F semirigid ureteroscope. The diverticular neck was balloon dilated to 18F, followed by fulguration with a 3F Bugbee electrode. A Double-J ureteral stent was placed antegrade from the diverticulum to the bladder, and an 8F nephrostomy tube provided external drainage. RESULTS: The mean operative time was 138.5 minutes, and the mean estimated blood loss was 10 mL. Neither of the diverticula contained calculi. The mean length of stay was 2.5 days, and there were no complications. The hemoglobin and creatinine values showed no significant change. Both patients remained asymptomatic at a mean follow-up of 38 months. CONCLUSION: Treatment of a caliceal diverticulum via a mini-perc technique is safe, effective technique with durable long-term results. It offers a less-invasive alternative to standard percutaneous treatment with larger access sheaths.

Optimization of monocarboxylate transporter 1 blockers through analysis and modulation of atropisomer interconversion properties.

We have previously described a novel series of potent blockers of the monocarboxylate transporter, MCT1, which show potent immunomodulatory activity in an assay measuring inhibition of PMA/ionomycin-induced human PBMC proliferation. However, the preferred compounds had the undesirable property of existing as a mixture of slowly interconverting rotational isomers. Here we show that variable temperature NMR is an effective method of monitoring how alteration to the nature of the amide substituent can modulate the rate of isomer exchange. This led to the design of compounds with increased rates of rotamer interconversion. Moreover, some of these compounds also showed improved potency and provided a route to further optimization.

Endophytic lesions: a predictor of failure in laparoscopic renal cryoablation.

BACKGROUND AND PURPOSE: Laparoscopic renal cryoablation is an emerging minimally invasive management option for T(1) renal lesions. In an analysis of patients treated with laparoscopic cryoablation for renal lesions, our objective was to compare the treatment outcomes in patients with exophytic/partially exophytic and endophytic (peripheral but completely intrarenal) lesions. PATIENTS AND METHODS: We retrospectively reviewed medical records of 32 consecutive patients with anterior renal lesions who were treated with laparoscopic renal cryoablation between 2003 and 2005. Biopsy samples were obtained from the majority of lesions intraoperatively. The lesions were managed with 17 gauge needles and two freeze/thaw cycles. Follow-up was performed with CT scans at 3, 6, and 12 months, and then yearly. Treatment failures were defined as continued enhancement on CT or growth of the lesion. Statistical analysis was performed using t-test, correlative, and multiple regression analysis. RESULTS: A total of 35 lesions in 32 patients were identified. Median lesion size was 1.9 cm. Median age was 67 years, with most patients having significant comorbidities. The median preoperative and postoperative creatinine level was 1.3 and 1.5 mg/dL (P = 0.38). Of the biopsy samples from 27 of 35 lesions, 18 showed renal cell carcinoma, 5 were found to be benign, and findings from 4 were inconclusive. Three lesions were completely endophytic. The median follow-up was 18 months, with treatment failures noted in 2 of 35 lesions (6%), both of which were endophytic (P < 0.0001). Multivariate analysis revealed that only the endophytic status of a lesion was a predictor of failure (P < 0.05). These were lesions that relied entirely on intraoperative ultrasonography for targeting, which suggests that failure was a technical error. CONCLUSIONS: Experience with renal cryoablation is still evolving. Our series further defines the role of laparoscopic renal cryoablation and its limitations in managing peripheral endophytic tumors. Completely endophytic lesions have a significantly higher risk of treatment failure. Reliance solely on intraoperative ultrasonography with no visual cues is a risk factor for treatment failure.